--------------------------------------------------------------HD614P080S
Do
GND
Fig. 16 Recommendable Layout of Crystal and Ceramic Filter
•
LOW
POWER
DISSIPATION MODE
The
MeV
provides
two
low power dissipation modes,
that
is,
a
Standby
mode
and
a
Stop
mode. Table
21
shows
the
function
of
the low power dissipation mode,
and
Fig. 17 shows the
diagram
of
the
mode
transition.
Table
21
Low Power Dissipation Mode Function
Condition
Low
Power
Instruction
Input/
Timer/ Recovering
Dissipation Mode
Oscillator
Instruction
Register
Interrupt
RAM
Output
Counter,
method
circuit
execution
Flag
function
pin
Serial
Interface
Standby
mode
SBY
Active
Stop
Retained
Active
Retained
*21
Active
RESET
Input,
instruction
Retained
Interrupt
request
Stop
mode
STOP
Stop
Stop
RESET*11
Stop
Retained
High
Stop
RESET
Input
instruction
impedance
*
11
STOP
mode
is
released
only
by
MCU
Reset.
Refer
to
Table 19 as for
the
values
of
the
registers
and
flags after releasing
stop
mode.
*21
Current
flows in
I/O
Circuit by I/O
p,in
state
at
stand-bY
mode,
because I/O circuit is active.
This
current
is
an
addition
to
stand-by
mode
power
dissipation.
Fig. 17
MCU
Operation Mode Transition
• Standby Mode
The
SBY instruction puts the
MCV
into the Standby mode.
In
the
Standby
mode,
the
oscillator circuit
is
active and timer/
281
counter
and serial interface continue working. On the
other
hand, the CPV
stops
since the clock related
to
the instruction
execution
stops. Registers,
RAM
and
Input/Output
pins retain
the
state
they
had
just
before going into the
Standby
mode.
The
Standby
mode
is
canceled
by
the
MCV
reset
or
interrupt
request. When canceled by the interrupt request, the
MCV
becomes an active mode and executes the instruction
next
to
the
SBY instruction_ At this time, if
the
Interrupt
Enable Flag
is
"I",
the
interrupt
is
executed.
If
the
Interrupt
Enable Flag
is
"0",
the interrupt request
is
held
on
and the normal instruc-
tion execution continues.
Fig. 18 shows the flowchart
of
the
Standby
Mode .
•
Stop
Mode
The
STOP instruction brings the
MCV
into
the
Stop
mode.
In this mode the oscillator circuit and every function
of
the
MCV
stop.
The
Stop
mode
is
canceled
by
the
MCV
reset. At this time,
as shown in Fig. 19, apply the
RESET
input
for more
than
tRC
to
get enough oscillator stabilization time.
(Refer
to
the
HAC
CHARACTERISTICS".) After the
Stop
mode
is
canceled,
RAM
retains the state it had just before going into the
Stop
mode after releasing
stop
mode by
MCV
reset,
the
values
of
the
B register, W register, X/SPX register, Y/SPY register, carry
and
serial
data
register are
not
guaranteed.
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